US Army infantryman Bradley Manning was convicted of leaking a large quantity of classified material to the whistleblower website Wikileaks between November 2009 and May 2010. He was arrested after confiding in celebrity hacker Adrian Lamo, who promptly contacted authorities. In a transcript of his internet conversation with Lamo, Manning asked, "If you had unprecedented access to classified networks 14 hours a day, seven days a week for eight plus months, what would you do?"

Manning was twenty years old when he enlisted in the US Army in 2007, and though holding only the baseline rank of Private First Class and experience working at Starbucks and Abercrombie and Fitch, he was assigned duties as an intelligence analyst. In 2008, he was disciplined for posting "sensitive information" in video messages on YouTube, but his security clearance was apparently not curtailed. Comments posted by Manning at Facebook reveal his growing frustration with the military's "Don't Ask, Don't Tell" policy, though when not wearing his uniform he seems to have been openly gay, lamenting a break-up with a boyfriend in his on-line posts. His last assignment was at Forward Operating Base Hammer near Baghdad, where he was arrested on 27 May 2010.

The breadth of material this Army private was able to access, copy, and purportedly release is breathtaking, and raises questions about the competence and efficacy of US military security. Manning was accused of providing Wikileaks with about 100,000 field reports from military officers in Afghanistan, and an additional quarter of a million confidential State Department cables. He was also accused of releasing numerous classified military videos, including footage of the 2009 Granai air strike in Afghanistan which left more than 100 civilians dead, and a 2007 video of US forces gunning down unidentified civilians in Baghdad, two of whom turned out to be Reuters journalists. In chat logs with Lamo, Manning described an easy mechanism for pilfering all this material — he brought music CDs to work, where he erased the music and loaded the discs with classified, digitized data. According to media reports, about 3,000,000 members of the US military have the same level of clearance Manning had.

Wikileaks and other free information advocates portrayed him as a hero, saying transparency is essential to democracy. US government officials denounced the leaks, claiming that they put American soldiers, allies, and diplomats in grave danger. Manning faced myriad charges under the Uniform Code of Military Justice, and has been jailed since July 2010. Salon writer Glenn Greenwald reported in December 2010 that Manning has been held in solitary confinement 23 hours a day during that time, barred from exercising, and kept drugged on anti-depressants "to prevent his brain from snapping from the effects of this isolation". Prominent US politicians ranging from Congressman Mike Rogers (R-Michigan) to former UN Ambassador John Bolton called for Manning's execution.

Electing to be tried in a military court, Manning was convicted of all but two of the charges against him. In a small victory, he was not convicted of treason. Sentenced to 35 years in prison, the judge credited Manning for the 1,293 days served before his trial, including 112 days credit to compensate for "abusive treatment" at Quantico. The day after the conviction, Manning announced through a statement that he was beginning hormone therapy and should henceforth be called Chelsea Manning. She will be eligible for parole in 2021, when she is 33.